Furnace construction



' June 24, 1930. I

L. H. HOSBEIN ET AL. FURNACE CONSTRUCTION 3 Sheets-Sheet v1 Filed Sept.17. 1928 June 24, 1930. L. H. HOIASBEIN Er AL FURNACE CONSTRUCTION Filedsept. 17. 1928 3, Sheets-Sheet [7206 7 6 lamflfioabezrz,

Welcom June 24, 1930. 1.. H. HOSBEIN Er AL 1,766,175

I FURNACE CONSTRUCTION Filed se t.1'1. 192s SiSheets-Sheet s ZZZ/670%:lowfl/Eoabam 027D Wdeoma Patented June 24, 1930 I UNITED STA TES PATENTOFFICE.

LOUIS H. HOSBEIN, 0F ,WINNETKA, AND 'OTTO VVELGOIVIIE, OF CHICAGO,ILLINOIS,

I ASSIGNORS TO M. H. DETRICK COMPANY, OF CHICAGO, ILLINOIS, ACORPORATION OF ILLINOIS summon conszrnuc'rxon I Application filedSeptember 17, 1928. Serial No. 306,571.

This invention relates to improvements in furnace construction andpertains particularly to the construction of furnace walls inassociation with fuel-feeding apparatus, such 'as oil burners andpulverized fuel burners whereby the fuel is injected into the combustionchamber through one or more of its walls.

Experience has shown that in the use of such fuel-feeding apparatus,particularly in large furnaces which are operated at high temperatures,wall portions adjacent the burners are subject to wear at a ratedisproportionate to the rate of wear occurring won the wall generally.We have ascertained that this has been due, in part, to inadequateprovision for control of the temperature of wall refractories adjacentthe burner, and to some extent to eroslve action of the injected fuel,and other influences.

Experience has also demonstrated that the b in the combustion chamber,particularly in installations in which the furnace is fired by aplurality of burners, wherein the firingfrom one burner may injureanother burner, particularly a burner which is not operating at the sametime. This condition arises, for example, when some of the burners areshut down when power requirements are low, or in furnaces equipped withboth oil and pulverized fuel burners which are operated interchangeably,that is, the oil burners being out of operation while the pulverizedfuel burners are operating, and vice versa.

It has also been ascertained that wall portions about the pulverizedfuel burners, as heretofore formed, are likely toaccumulateencrustations or accretions of coke and ash which are likelytointerfere, to some extent.

with the proper operation of burners, and to I contribute todisintegration of the wall refractories.

The present invention has for its object adequate protection and avoidinterference with their proper operation, and which will urners areliable to injury, from the heat 7 certain details of which willafi'ordthe burners 1 exposed to the furnace heat and forwall re- ..fractoriesaround the burner openings.

Another object is the provision of such a construction which may beinstalled and repaired with facility and in which the various elementsmay be interchangeable and of standardized form.

Other objects include the provision of i'm-' proved features andelements of the construction as hereinafter pointed out and claimed.

Further objects will be pointed out or indicated hereinafter, or will beapparent to one skilled in the art upon an understanding of theinvention or its employment in practice. 3 In thedrawings forming a partof this specification we show one form of construction embodying theinvention, but it is to be understood that this is presented for purposeof illustration only and is not to be given any interpretationcalculated to limit'the claims short of the true and most comprehensivescope of the invention in the art.

In said drawings Fig. 1 is a sectional elevational view of a portion ofa furnace wall provided with burner openings and constructed in accordance with the invention, same corresponding to a sectionon line 1.-1 ofFig. 2;

Fig. 2 is a part elevation of the interior of such a wall and showingalso parts of'the exterior sheathing;

Fig. 3 is another sectional along line 33 of Fig. 2;

Fig. 4 is a detail in the nature of a section on line H of Fig. 5;

Fig. 5 is a part horizontal line 5-5 of Fig. 2, and

' Fig. 6 is a perspective view illustrating the wall constructionadjacent the burner o enin A wall construction with which the presentinvention may be employed to particuar advantage is that described andclaimed in the U. S. Patents Nos. 1,747,822 and 1,7 t7,823 to RaymondJ). Foltz, and a wall elevation as section as along of that general typeis presented herein' by ranged to discharge 1nto the furnace chamber,being supplied with fuel from a duct or ducts .14 and with air from anair duct or ducts 15. The frame carries horizontal members 16, extendingfrom one upright to another and affording support for the wall hangers17 which may have the same general form and arrangement as described inthe applications referred to above. These hangers carry thestraight'wall sections made up of flat refractories 18 and jointrefractories 19, said hangers also acting as spacing members to maintainthe wall sections spaced inwardly away from the frame members. Above theburners are disposed series of curved hangers 20 having hooked arms 20at their upper ends for engagement retained with certainof the members16 and horizontal arms 20 at their lower ends for abutment withhorizontal members 21 which are carried on the frame. Between these arms20 and 20, the upri ht body portion of these hangers is curved outwardlyat its upper part and inwardly at its lower part and provided withlateral flanges 20 and 20 conforming to the curves of these respectiveportions. Inclined shelves 20 extend inwardly from the hanger bodyportions at about the point where the curvature reverses, and bottomflanges 20 are provided along the lower margins of the arms 20 andterminate at depending stop members 20 On the flanges 2O are suspendedslotted tile 22 which depend vertically into contact with the casing ofthe burner 12, said tile being susceptible of a limited-extent ofvertical play on said flanges and being retained against shiftingoutwardly by the stop members 20 which are spaced inwardly from theframe members 10. On the inner ends of the flanges 20 and on the flanges20 are shiftably supported supplemental tile suspension members 24 andwedge-shaped tile 25, both being in the general form and arrangement asillustrated and described in U. S. Letters. Patent No. 1,544,580, saidwedge-shaped tile being associated to form. a convex wall portioncurving inwardly and upwardly in the furnace chamber above the burner.By virtue of the connection by which the tile 25 are anchored to thehangers 20, they are susceptible of vertical movement, but securelyagainst falling out of the wall.

' cured by Flat brick 26 are inserted above the uppermost tile 24 andbelow the shelves 20 and with the hanger flanges 20. Thus, they aresupported independently of the refractories below the shelves and aresusceptible of upward movement while at the same time remaining anchoredto the hangers in such fashion that they are held against displacementout of the plane of the wall. Joint refractories 19 are placed on top ofthe re fractories 27 and arranged in overlapping relationship with thelowermost refractories of the superj acent wall sections, compressiblerefractory material being arranged on top of said joint refractories toaccommodate upward expansion of the refractories 27 and 19' and maintaina closed joint between the sections. By virtue of this construction,therefore, the furnace wall immediately above the burner openingprojects into the furnace chamber beyond the general vertical plane ofthe-wall, and takes a regular convex form'which gives the wall openingfor the burner an inward flare.

At the end of the series of hangers 20 are disposed the hangers 28 whichare likewise supported on members 16 and 21 and have the upper parts oftheir body portions curved outwardly in conformity with thecorresponding parts of the hangers 20. Their lower portions, however,are provided with vertically extending lateral flanges 28 whichterminate at horizontal shelves 28". Flat re fractories 29 with slottedouter ends are engaged with the flanges 28 and above them wedge-shapedrefractories 25 and refractories 27 are supported on and anchored to thehangers 28. Below the refractories 29, the wall is continued downward insubstantially vertical direction by refractories 30, 32

and 34 at the side of the burner openings.

The manner in which these last-mentioned refractories are maintained inplace at the sides of the burner openings is illustrated generally-inFigs. 3 and 4. On a suitable supporting sill 35 wedge-shapedrefractories 34 are laid in such relationship as to form a sort ofpilaster extending inwardly from the general vertical plane of the wall.These are disposed in superimposed courses and are anchored at theirouter ends, as in the manner described in the patent above referred to,to the arcuate flanges 36 of horizontal anchor castings 36. These anchorcastings are sebolts 37 to the outer frame members or .to the sheatingplates 38 secured. thereto,

' T-shaped slots receiving marginal portions A-continuous sheathing 5at. 47 in and extending beyond the 'ly while possessing a desirablefreedom for shifting laterally. Depending on circumstances such as thespacing of the burner openings and their distance from the side walls,the width of these pilasters may be increased where desired by theinterposition of parallel-sided refractories 32 between thewedge-shapedrefractories 34, said parallelsided refractories being seton edge and their of the anchor castings 36. By this pilasterarrangement, the sides of the burner openings are given a curvedcontour, so that the burner opening flares toward the furnace chamberand the wall extends for a considerable distance beyond the dischargeends of the burners. 4

Likewise, an inwardly flaring wall portion is provided at the bottom ofthe burner openings by the wedge-shaped refractories 39. The lowermostcourse of these refractories is laid on an expansion cushion 40 ofcompressible refractory material, which cushion rests on the supportingsill structure 35, and superimposed courses of similar wedge-shapedrefractories are laid on them in such fashion as to form. an arch-likestructure curving downwardly toward the furnace chamber burners. Therefractories of this structure are maintained in place by their ownweight and are connected in pairs by retaining members 41, the uppermostcourseabutting a ledge 43 which is built up of ordinary fire-brick andformed with air passages 43 at intervals in its lower part. Where burneropenings are relatively close'together one above another, as in theexample illustrated, the intervening wall portion may be formed ofrefractories 44 having bevelled inner corner portions and slotted outerend. portions. These are arranged in a horizontally running coursesupported on the lower burner casing and projecting for a substantialdistance inwardly beyond the ends of the burner. They are maintained inposition by anchorage on an anchor bar 45, the flanged margin of whichis engagedin their slots, said bars being retained by bolts 46 againstshifting inwardly. The tops of the pilasters, Where they jut inwardlyfrom the superjacent wall portions,

may be capped off With plastically appliec refractory material insuitable contour as indicated at c in g Wallis provided by the plates 38and the frame members 11, so that an air chamber is formed between therefractory This air chamber may be subdivided into horizontal lanes bypartition bricks 42 supported on the hangers 17. The air chamberprovidedat suitable locations with air inis lets through the sheathing wall, asindicated .units retained thereby,

wall and such sheathing wall. b

Fig. 2, which inlets prefer a'bly are with pneumatic fuel feeding.

damper controlled. In the construction illustrated, air inlets are alsoafforded by thepassages 43 at the bottom of'the wall, which passages aresupplied with air by way of passages 48* of the hollow wall of the ashhopper 48. An outlet duct 49 also has communication with the air chamberor air lanes of the Wall at points spaced from the various air inlets.through the duct 49, external air will be caused to enter through theinlets 47 and the passages 43 and to flow through the air chamber incontact with-the outer faces of the wall refractories and the exposedportions of the hangers and anchoring members,

Suitable suction being maintained and also in contact with the surfacesof the burner casings exposed in the air chamber. Thus an effectivecooling of the wall refractories and their supporting andanchoringembers is maintained, and dead air is not permitted to remain in thebulging portions of the wall about the burner openings. As aconsequence, therefractories in the bulging portions of the wall,whichbecause of their position in the furnace chamber might be subjectedto heating to an extent disproportionate with the heating ofrefractories in other portions of the wall, may be kept at a temperaturesufficiently low to. avoid their rapid destruction by slagging and otherdisintegrating influences, so that their term of serviceability will becommensurate with that of the other wall refractories generally. Thebulging wall portions about the burners, consequently, exercise threeimportant functions, viz: they permit the burners being inset into thehorizontal area .of the wall and afford them the necessary shading andprotection from the heat of the furnace champarticularly from the flameof other without necessitating wall they keep'slag and ber anddischarging burners, any thickening of the encrustations away from theburners; and,

being themselves subjected to cooling influence, they are effective tolimit the heating of the burner portions with which they are associated.

The construction vantages in combining flexibility of various portionsof the wall with stability of the strltcture as a whole. For example,the various supporting and anchoring members of the wall, such as'thehangers 20 and 28 and the members 36, 46, etc. have a desirable freedomfor movement, so that the assembled as well as the individualrefractories, may adjust themselves in the structure to accommodateexpansion, ut at the same time all are definitely anchored in suchfashion that they cannot be displaced out of the desired relationshipwith associated portions, either by their own weight or by thermalexpansion or by pulsations or vibrations such as frequently occur Thesectional possesses particular adthe fuel jets and minimizes erosiveaction on the refractories.

The construction makes possible the desired shading of the burnerswithout increase in t 1e thickness of the refractory wall at those 10ations. This is important from the standpo'nt of controllingtransmission of heat through the refractory wall and also from thestandpoint of cost, the latter from the fact that the various shapes ofrefractories may be of uniformsize throughout the structure, and bysuitable cooling control the normal wear of the refractories may beequalized over the wall.

What we claim is:

1. In a furnace, an upright furnace cham ber wall formed of refractoriesarranged in superposed horizontally running courses, said wall beingprovided with a burner opening therethrough, refractories above andadjacent the burner opening being offset 1nwardly with respect to thegeneral inner surface plane of the wall to form an inwardly protrudingwall portion about the burner opening.

2. In a furnace, a furnace chamber Wall formed of refractories and ofapproximately uniform thickness, said 'wall having a portion bowedinwardly so as to protrude into the furnace chamber beyond the generalplane of the inner wall surface, and the wall afi'ording a burneropening bounded by said protruding portion.

3. In a furnace, an upright furnace cham ber wall formed of refractoriesand of substantially uniform thickness, said wall affording a-burneropening and having portions adjacent said opening bowed inwardly beyondthe general plane of the inner wall surface and forming inwardly flaringwalls for the burner opening.

4. In a furnace, an upright furnace chamber wall formed of refractoriesand afl'ording a burner opening and having pilasters at the sides of theburner opening and a protruding portion above the burner opening, saidpilasters and protruding portion projecting inwardly in the furnacechamber beyond the genfiral inner surface plane of the wall and eacposed refractories. a I 5. In a furnace,.in combination, an uprightfurnace chamber wall, a fuel-discharging-device extending. through thewall, sald wall having portions adjacent the, fuel-discharging devicebowed inwardly of the furnace chamber beyond the'fuel-discharging beingformed of a plurality of superdeviceand the general inner surface planeof v the wall.

6. In a furnace, in combination, a hollow.

upright furnace chamber wall affording a burner opening therethrough andincluding a refractory lining, said refractory lining approximatelyuniform thickness and being bowed inwardly adjacent the burner opening,and the air chamber provided with iulet and outlet arranged to directair circulation in the air chamber across the outer surfaces of saidbowedrefractory wall portion.

8. In a furnace, in combination, refractories arranged to form anupright furnace chamber wall having portions projecting into the furnacechamber beyond the general surface plane of the wall to form walls of aburner opening, a frame arranged externally of said wall, and anchoringmembers connecting refractories in said inwardly projecting portions tosaid frame to holdsaid refractories' against displacement inwardly fromthe wall.

9. In a furnace, a furnace chamber wall built up of refractories and ofsubstantially uniform thickness, said wall afiording a burner openingand having portions formed of refractories anchored in superposedrelationship and protruding inwardly of the furnace chamber adjacentsaid opening, and means for directing cooling air across outersurfacesof the refractories in said protrud mg portions.

10. A furnace structure comprising a refractor wallportion having itsinner sur-v face su stantially in a common plane, a fueldischargingdevice extending transversely of said wall portion to dischargefuel intothe furnace chamber, hangers supported'adjacent said fuel-dischargingdevice, and refractories supported on said hangers in superposedhorizontally running courses to form a wall part conjoining said wallportion and rotruding inwardly of the furnace chamber eyond the generalinner surface plane of the wall portion and adjacent thefuel-discharging device.

11. A furnace structure as specified in claim 10 and wherein said wallpart is of approximately the same thickness as said wall portion. r

12. A furnace structure as specified in claim 10 and wherein saidhangers and refractories are movable relative to the wall portion andfuel-discharging device to accommodate thermal expansion. 13. A furnacestructure as specified in claim 10 and wherein the inner surface of saidwall part flares from the fuel-discharging device toward the furnacechamber.

'14. A furnace structure as specified in claim 10 and wherein saidinwardly protruding wall device.

15. Furnace structure comprising, in combination, a wall supportingframe, refractory Wall sections supported on the frame with their innerfaces approximately in a common general wall plane of the furnacechamber, supports carried on the frame, and refractories supported byand anchored to said supports and off-set inwardly in the furnacechamber from said general plane to form an inwardly protruding wallportion, said inwardly protruding wall portion conjoining the wallsections to maintain continuity of the wall.

16. In a furnace, a refractory furnace chamber wall affording a burneropening, portions of the wall adjacent the burner opening being bowedinwardly into the furnace chamber, said inwardly bowed portions being ofapproximately uniform thickness, and a burner set into the.wall withinthe burner opening in position to discharge into the furnace chamber.

172' In a furnace, an upright refractory wall affording a burner openingtherethrough, said wall having portionsbowed inwardly into the furnacechamber adjacent the burner opening, said inwardly bowed portions beingmade up of a plurality of refractories each having but a single faceexposed within the furnace chamber, and means engaging outer portions ofsaid refractories to anchor them in the structure.

In testimony whereof we have hereunto subscribed our names.

LOUIS H. HOSBEIN. OTTO WELCOME.

part is in overhanging relationship to the discharge path of thefuel-discharging

